class Solution {
    public int maxProfit(int[] prices) {
        int n = prices.length;
        int[][] dp = new int [n][2];

        for (int i = 0; i < n; i++) {
            if (i-1 == -1) {
                dp[i][0] = 0;
                dp[i][1] = -prices[i];
                continue;
            }
            dp[i][0] = Math.max(dp[i-1][0],dp[i-1][1] + prices[i]);
            dp[i][1] = Math.max(dp[i-1][1],-prices[i]);
        }
        return dp[n-1][0];
    }
}

class Solution {
    public int maxProfit(int[] prices) {
        int n = prices.length;
        int[][] dp = new int[n][2]; 

        dp[0][0] = 0;
        dp[0][1] = -prices[0];

        for (int i = 1; i < n; i++) {
            dp[i][0] = Math.max(dp[i-1][0], dp[i-1][1] + prices[i]);
            dp[i][1] = Math.max(dp[i-1][1], dp[i-1][0] - prices[i]);
        } 

        return dp[n-1][0];
    }
}